Parkinson's disease (PD) is a progressive disorder of the nervous system, meaning symptoms worsen over time. According to the Parkinson's Disease Foundation (PDF), approximately one million people in the U.S. live with PD. Worldwide, the number is an estimated seven to 10 million.

PD affects movement and develops gradually - sometimes manifesting itself with a barely noticeable tremor in one hand in its early stages. While tremor is the most commonly associated symptom, other signs include stiffness of the limbs, slowness of movement, slurred or stiff speech, and impaired balance and coordination.

Scientists continue to search for the cause of PD, studying both genetic and environmental factors. Current research examines how the disease progresses, looking to find possible environmental factors, such as toxins, that may trigger PD.

There is no cure for PD, and no way to predict how symptoms will affect an individual. For some patients, tremor may be the main symptom, while others experience only minor symptoms. Medications can help relieve symptoms as well as dietary changes.

But should your fruits and veggies be conventional crops or organic?

Is Organic Better?

Choosing an organic-based diet might be a healthier option for helping prevent the onset of PD, or helping those already diagnosed with the disorder.

Numerous studies demonstrate the health risks of exposure to pesticides, which are used to grow conventional crops. In 2009, researchers at UCLA found that Central Valley, Calif. residents who lived within 500 meters of fields sprayed between 1974 and 1999 had a 75 percent increased risk for developing Parkinson's disease.

They noted in their paper, published in the American Journal of Epidemiology, that "Parkinson's disease has been reported to occur at high rates among farmers and in rural populations, contributing to the hypothesis that agricultural pesticides might be causal agents."

And yet another recent study, published in the journal Neurology, strongly indicates the risk factor for Parkinson's disease and exposure to pesticides. Researchers found approximately twice an increase in risk of Parkinson's associated with exposure to paraquat (a weed killer) or maneb/mancozeb (a fungicide used on crops).

Based on mounting evidence that links pesticides to the development of Parkinson's, there are steps you can take.

Buy organic whenever you can. The term organic does not guarantee pesticide-free foods; "organic" labeling means that synthetic chemical pesticides have not been used to grow or store the food. For more in-depth information, you can visit the Environmental Working Group (EWG) website to read its Shopper's Guide to Pesticides in Produce.

According to EWG, "consumers can markedly reduce their intake of pesticide residues and their exposure to antibiotic-resistant bacteria by choosing organic produce and meat."

You can also try to shop locally - at your local farmer's market, for instance - to gain a better understanding of where your food comes from. You can ask how weeds and pests are managed during the growth of crops.

And, in your home, eliminate or reduce your use of pesticides. Look for alternatives to toxins, like cleaning up dining areas immediately after eating to keep out mice and insects. Learn more about safe chemicals by visiting Safer Chemicals, Healthy Families.

Is There a Parkinson's Diet?

While there's no special diet that's been proven to slow or prevent the progression of Parkinson's disease, there are some dietary recommendations that may help alleviate symptoms. Before attempting any new changes, it's best to speak to your doctor about creating the best plan for you.

Fiber

Eating a diet rich in fruits and vegetables may help protect nerve cell function. And, many fruits and vegetables are high in fiber, which is important to prevent constipation, a common symptom in PD.

The Mayo Clinic suggests eating a nutritionally balanced diet that contains fruits, vegetables, and whole grains. "A balanced diet," according to Mayo Clinic, "also provides nutrients, such as omega-3 fatty acids, that may be beneficial for people with Parkinson's disease."

Peppers

Piling your plate with peppers may help protect against Parkinson's. According to a recent study from the University of Washington, consumption of edible Solanaceae revealed decreased risk of developing Parkinson's, with peppers displaying the strongest association.

Solanaceae is a flowering plant family, with some species producing foods that are edible sources of nicotine (including peppers). In this particular study, researchers focused on the effects of nicotine and PD.

This study was the first to examine dietary nicotine and its potential protective effect against Parkinson's. The apparent protection from Solanaceae vegetables occurred mainly in men and women with little or no prior use of tobacco, which contains much more nicotine than the foods examined in the study. While more research is needed, the study suggests the possibilities of diet modifying susceptibility to neurological disease.

Flavonoids

Found in plants and fruits, flavonoids are plant-based compunds with powerful antioxidant properties, which help prevent and repair cellular damage. Flavonoids can also be found in berry fruits, chocolate, and citrus fruits, such as grapefruit and oranges. One study suggests that regularly eating flavonoids may reduce the risk of developing PD, particularly in men. Men who incorporated the most flavonoids into their diet were 40 percent less likely to develop PD. Flavonoid-rich foods include berries, apples, oranges, and beverages such as tea and red wine.

So does this mean that eating several servings a day of berries will ward off PD? Not necessarily.

The study didn't show a link between eating these foods and developing PD; so future research is still needed to confirm whether or not eating flavonoid-rich foods can prevent progression of the disease.

"Still," said Xiang Gao, M.D., Ph.D., assistant professor of medicine at Harvard Medical School and co-author of the paper, "it is not a bad idea to include berries in your diet, as they have other beneficial effects on other diseases."

Protein

Patients with PD are prone to osteoporosis, which poses more of a danger to someone with the disease. It's important to maintain bone health and include calcium and vitamin D into your diet.

The best sources of calcium come from milk and dairy products, like yogurt and hard cheese. Other calcium-rich foods include tofu, calcium-fortified soy beverages, and dark leafy greens, but these non-dairy sources may not be absorbed as well by the body as dairy sources.

Maintaining Balance

The most important thing to remember is that PD symptoms will vary from person to person, and at each stage of the disease. Your unique nutritional needs should be based on the issues you face at a particular stage. While eating well and maintaining a healthy weight are certainly emphasized during the early stages of PD, as the disease progresses, your dietary needs might need to be adjusted based on changing symptoms.

Sources:

Costello S. Cockburn M. Bronstein J. Zhang X. Ritz B. Parkinson's Disease and Residential Exposure to Maneb and Paraquat From Agricultural Applicants in the Central Valley of California. American Journal of Epidemiology. 2009.

Fahn S. Chasing the Cure. Parkinson's Disease Foundation News & Review. 2009.

Greener M. Pesticides and Parkinson's disease pathogenesis: the controversy continues. Progress in Neurology and Psychiatry. 2013.

Searles S., Franklin G., Longstreth Jr. W.T., Swanson P., Checkoway H. Nicotine from Edible Solanaceae and Risk of Parkinson Disease. Annals of Neurology, 2013.